This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Dietary Control Alone Versus Dietary Control Plus Use of Proton Pump Inhibitors to Treat Pediatric Hoarseness (NCT00637416), a randomized phase 4 study. The primary outcome is Change in Condition Over Treatment Period.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00637416 |
| Phase | Phase 4 |
| Condition | Dysphonia |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 9 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Kansas Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned pediatric hoarseness, with dysphonia listed as the condition. The registry record does not report further eligibility details, such as age limits or the clinical criteria used to define hoarseness. Enrollment was 9, but the primary outcome record states that zero participants were analyzed.
Intervention
The intervention arm was assigned lansoprazole together with dietary control. The registry identifies lansoprazole as a drug. Details of the dietary control program, including its specific instructions and how adherence was assessed, are not reported in the registry record.
Comparator
The comparison arm was assigned placebo together with dietary control. The registry lists placebo as an intervention and describes the arm as dietary control and placebo. Further information about the placebo or the dietary program is not reported in the registry record.
Primary question
The primary question was whether change in condition over the 3 months of treatment differed between the assigned groups, as assessed with the voice assessment protocol-Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS). The record says the study was stopped early, data were not collected, and zero participants were analyzed. It therefore contains no primary-outcome comparison that answers this question.
3. Trial Design
The registry classifies the study as a randomized, double-masked, parallel-group trial in phase 4. The planned comparison was lansoprazole plus dietary control versus placebo plus dietary control. In a parallel-group design, participants are assigned to one treatment group and remain in that group for the planned comparison. Randomization is intended to support a fair comparison of groups, while masking is intended to limit the influence of treatment knowledge on participants or study personnel. The record does not say which people were masked or how randomization was carried out.
The sponsor was the University of Kansas Medical Center. The recorded start was 2008-03, and primary completion was recorded as 2009-07. The status is terminated. Enrollment was 9. The primary outcome description says the study was stopped early and that data were not collected; the reason for stopping early is not reported in the registry record. The record does not provide further detail on recruitment, treatment delivery, adherence, or follow-up.
Although randomization and masking are useful design features, they cannot produce a treatment-effect estimate when the intended outcome was not collected and no participants were analyzed. The registry does not report a completed comparison, an analysis population beyond the statement that zero participants were analyzed for the outcome, or a statistical analysis plan. The intended design should therefore be distinguished from the evidence available in the posted results: the former describes how the study was organized, while the latter records no primary-outcome findings.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Lansoprazole and Dietary Control | Placebo and Dietary Control |
|---|---|---|
| STARTED | 4 | 5 |
| COMPLETED | 3 | 3 |
| NOT COMPLETED | 1 | 2 |
Reasons for not completing this period:
| Reason | Lansoprazole and Dietary Control | Placebo and Dietary Control |
|---|---|---|
| Lost to Follow-up | 1 | 1 |
| Unable to take study drug | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: Study was stopped early, data were not collected, and zero participants were analyzed.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Lansoprazole and Dietary Control | Placebo and Dietary Control | Total |
|---|---|---|---|---|
| Participants analysed | 4 | 5 | 9 | |
| Age, Categorical: <=18 years | Participants | 4 | 5 | 9 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 0 | 0 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Gender: Female | Participants | 2 | 2 | 4 |
| Gender: Male | Participants | 2 | 3 | 5 |
| Region of Enrollment: United States | participants | 4 | 5 | 9 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Condition Over Treatment Period, measured over 3 months.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was change in condition over the treatment period, with a timeframe of 3 months. The registry says change was measured using the voice assessment protocol-Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS). The named components concern features of voice: grade, roughness, breathiness, asthenia, and strain. The record does not report the scoring range, how ratings were combined, who performed the assessments, or what amount or direction of change would be considered meaningful.
Generally, a change endpoint is intended to describe how a measured condition varies over time rather than only its status at a single assessment. A structured voice assessment can organize judgments about vocal qualities into defined dimensions, allowing investigators to compare assessments using a consistent framework. These are general reasons to use such an endpoint; the registry does not explain its specific rationale for choosing GRBAS or give details of its measurement procedure.
In this trial, the planned measure cannot be interpreted because the record states that data were not collected and zero participants were analyzed. There is no reported change score, group contrast, or estimate of precision. The endpoint definition tells readers what the study intended to measure, not what happened to participants during treatment.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry records a planned randomized comparison but no analyzed primary-outcome data. It states that the study was stopped early, data were not collected, and zero participants were analyzed for change in condition. Consequently, there is no reported estimate of change in either group and no reported estimate comparing the groups. The posted results do not establish whether the groups differed on the GRBAS outcome.
Enrollment was 9, but enrollment alone is not an outcome result. It should not be treated as the number analyzed or as evidence that the planned comparison was completed. The record does not explain how enrollment was distributed between groups, and the primary outcome description explicitly reports zero participants analyzed. There is no basis in the registry record for estimating a treatment effect, its uncertainty, or the precision of a comparison.
Randomization is useful because it is designed to reduce systematic differences between groups at the start of a trial. Double masking can also limit some sources of bias. Those design features do not overcome the absence of outcome measurements. Without analyzed outcomes, there is no observed group contrast to interpret and no confidence interval or hypothesis test for the primary endpoint reported in the registry record.
The safety entries are separate from the missing primary outcome. The registry lists 4 participants at risk for serious adverse events in the lansoprazole and dietary control group and 5 in the placebo and dietary control group; zero affected participants are listed in each group. These entries do not supply evidence about the primary voice outcome. Nor should zeros in these small listed groups be read as proof that an adverse event could not occur.
The reason for early termination, the planned sample-size justification, and the study's intended statistical analysis are not reported in the registry record. Without that information and without outcome data, readers cannot determine whether the study ended for operational, recruitment, safety, or other reasons. No conclusion about comparative effectiveness follows from the missing outcome results. The central statistical finding is the absence of an analyzable primary-endpoint comparison.
9. Statistical Methods Explained
The registry identifies randomization, double masking, and a parallel-group structure. These terms describe design choices, not statistical results. In general, random assignment is used to make group membership less dependent on participant characteristics. This supports interpretation of a group contrast, provided the assignment process is implemented as intended and outcomes are collected and analyzed appropriately. The registry record does not describe the randomization method, allocation concealment, or whether assignment was stratified.
In a parallel-group trial, each participant is assigned to a treatment strategy rather than crossing between strategies. Here, the listed strategies were lansoprazole with dietary control and placebo with dietary control. In general, masking can reduce the chance that expectations influence treatment behavior, outcome assessment, or reporting. The record calls the trial double-masked but does not identify the masked roles or describe how masking was maintained. It also does not report whether masking was assessed.
The primary outcome is described as change in condition measured with GRBAS over 3 months. Statistical analysis of a change measure typically requires a clearly specified scoring rule, assessment schedule, and definition of the contrast between groups. Depending on how an outcome is scored and distributed, analysts may use different methods to estimate a group difference and its uncertainty. Those choices cannot be inferred from the endpoint name. The scoring details, planned model, and treatment-effect measure are not reported in the registry record.
General statistical interpretation relies on both an estimate and its uncertainty. A confidence interval is a way to express the range of values compatible with the data and a specified statistical procedure. A narrow interval generally indicates greater precision than a wide interval, while an interval that spans meaningfully different possibilities may leave the result inconclusive. A p-value, when used, describes how compatible data are with a specified null model under stated assumptions; it is not the probability that a treatment works. Neither a confidence interval nor a p-value for the primary outcome is reported in this record, because no participants were analyzed for that outcome.
Over-dispersion is a general concern when observed variation exceeds what a chosen statistical model assumes. If relevant, it can make standard errors too small and confidence intervals too narrow unless the analysis accounts for it. Whether over-dispersion was a concern for this trial is not reported in the registry record. More broadly, model selection, distributional assumptions, covariate adjustment, and handling of repeated assessments are not reported. No analysis method should be attributed to the investigators without a registry description.
Multiplicity arises when an analysis tests or estimates several outcomes, dimensions, time points, or group contrasts. In general, examining many comparisons can raise the chance of at least one apparently notable result arising by chance. A protocol may address this by prioritizing a primary comparison or adjusting interpretation for multiple testing. The registry indicates that the primary outcome has several categories or time points and does not reduce it to one comparison. A multiplicity strategy is not reported in the registry record. Because no endpoint data were collected, multiplicity does not create a result to interpret in this trial; it remains a question about the intended analysis.
Sample-size calculations are planning tools, not evidence that a study has sufficient observed information. A planning illustration based on assumed effects and statistical conditions describes a hypothetical design requirement. It is not observed power and does not replace analysis of outcomes. The registry record does not report the trial's own sample-size justification. With no analyzed primary endpoint and no observed group contrast, there is no trial-based effect estimate or precision assessment to interpret. Any planning quantity should therefore remain distinct from a result of the randomized comparison.
Analysis populations also matter. In general, an intention-to-treat analysis compares participants according to randomized assignment, while other populations may apply additional eligibility or treatment-received criteria. The choice can affect how the treatment contrast is interpreted, especially when participants discontinue or have missing outcomes. The registry does not report the planned analysis population or a completed population analysis. For the primary endpoint, it explicitly states that zero participants were analyzed. This prevents assessment of how assignment, treatment received, and follow-up contributed to an outcome estimate.
10. Multiplicity, Missing Data and Analysis Populations
The primary endpoint is described using GRBAS, whose name includes several voice-assessment dimensions. The registry also indicates that the primary outcome has several categories or time points and is not reduced to a single comparison. It does not report how those dimensions or time points were to be combined, prioritized, or handled in statistical testing. A plan for controlling or interpreting multiplicity is not reported in the registry record.
In general, multiple outcome comparisons can make isolated findings harder to interpret because the chance of finding an apparently unusual result can increase as more comparisons are considered. A prespecified primary contrast, a hierarchy of outcomes, or an adjustment procedure can help clarify the intended interpretation. These are general approaches, not methods attributed to this study. No such approach is reported in the registry record, and there are no outcome results to which a multiplicity adjustment could be applied.
Missing-data handling is also not reported. More specifically, the primary outcome description says the study was stopped early, data were not collected, and zero participants were analyzed. This is not a situation in which the record presents a partially observed endpoint and explains how missing values were handled; it reports no analyzed primary-endpoint observations. The reason for stopping early and any follow-up information are not reported in the registry record.
The record does not specify an intention-to-treat population, a per-protocol population, or another analysis population. It therefore does not support a comparison of results across analysis populations or an assessment of whether missing outcomes altered an estimate. No statistical plan for missing data, sensitivity analysis, or imputation is reported. The absence of these details limits evaluation of the intended analysis, while the absence of collected outcome data means there is no primary effect estimate to recover from the posted results.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Lansoprazole and Dietary Control | 0 | 4 | 0.0% |
| Placebo and Dietary Control | 0 | 5 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Lansoprazole and Dietary Control | 0 of 4 |
| Placebo and Dietary Control | 0 of 5 |
The registry lists serious adverse event counts by group. In the lansoprazole and dietary control group, 4 participants are listed as at risk and zero as affected by a serious adverse event. In the placebo and dietary control group, 5 are listed as at risk and zero as affected. The record also lists zero participants affected by other adverse events in both groups, with the same at-risk counts. These are the posted counts, not comparative estimates of risk.
The death counts are not reported in the registry record. No serious adverse event terms are listed. The zeros should be read as the entries recorded for these groups, not as proof that the underlying risk was absent. The listed groups are small, and counts alone do not establish that the groups had equivalent safety experience. The record does not provide further detail about event definitions, collection procedures, follow-up duration, or how the at-risk group counts were determined.
These safety entries do not change the primary-outcome status: the study was stopped early, primary endpoint data were not collected, and zero participants were analyzed for that endpoint. Safety counts and voice-assessment results address different questions.
12. What the Result Does, and Does Not, Mean
The result that can be stated from the registry is procedural rather than comparative: this randomized, double-masked study was terminated early, and the record reports no collected or analyzed data for its primary voice outcome. It does not provide an estimate of change in condition for either group or a statistical comparison of lansoprazole plus dietary control against placebo plus dietary control.
This absence of an estimate is not evidence that the two strategies produced the same result. It is also not evidence that one strategy produced more or less change. A conclusion about direction or magnitude would require outcome measurements and an analysis, neither of which is reported. The record supplies no confidence interval, p-value, or other measure of precision for the primary endpoint.
Enrollment of 9 participants does not resolve this limitation. The endpoint description says zero participants were analyzed, and the registry does not report the distribution of enrollment between groups. The at-risk counts in the safety entries are not a substitute for primary-outcome observations and should not be used to infer a treatment effect on hoarseness.
The trial's design features describe an intended comparison, while the posted results document that the comparison did not yield an analyzed primary outcome. The reason for early termination, the planned analysis, and a study-specific sample-size justification are not reported in the registry record. Those gaps prevent a fuller account of why the study ended and how its intended analysis would have been conducted. The appropriate interpretation is limited: the registry record does not answer the primary clinical question.
13. Why This Trial Matters Statistically
This trial illustrates an important distinction between a planned experiment and an analyzable result. Randomization, masking, and a defined primary endpoint can strengthen a study's design, but they do not by themselves produce evidence about a treatment contrast. Outcome collection and analysis are necessary to estimate what happened in the groups and how uncertain that estimate is.
The record also shows why enrollment and analysis counts should not be treated as interchangeable. It records enrollment of 9, yet the primary outcome description reports zero participants analyzed. The registry does not report how participants were allocated or why the study stopped early. Without those details, even a basic account of the path from enrollment to outcome analysis is limited.
From a statistical perspective, a missing estimate is not a null finding. It cannot support a claim of no difference, nor can it support a claim of benefit or harm on the primary voice outcome. Distinguishing these possibilities matters when readers encounter trial registrations alongside completed studies with estimates and measures of uncertainty.
The safety counts further illustrate the limits of descriptive event totals. Zero affected participants are listed in each group, but the record does not provide enough information to infer comparative safety or rule out events. The primary outcome and safety records must be interpreted as separate forms of information, each bounded by what was recorded.
Finally, the record identifies unanswered methodological questions, including the reason for termination, the statistical plan, and the handling of multiple endpoint dimensions or time points. Recognizing these limits is useful in evidence appraisal: a transparent account of absent data is itself important, but it does not substitute for the results needed to answer the trial's primary question.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The main trial-specific limitation is that the study ended early and the primary outcome data were not collected. The record states that zero participants were analyzed, leaving no estimate of change in GRBAS and no comparison between the randomized groups. As a result, the precision and direction of any possible treatment contrast cannot be assessed.
The registry does not report why the study was stopped early. It also does not give further detail about the recruitment process, participant eligibility, treatment adherence, follow-up, or the number assigned to each group. Although enrollment was 9, the primary endpoint's analysis population is explicitly zero; the record does not explain the path from enrolled participants to the absence of analyzed outcomes.
Important measurement details are not reported, including the GRBAS scoring procedure, assessment schedule beyond the 3-month timeframe, assessor roles, and the meaning of a clinically important change. The registry also does not describe the statistical analysis plan, the intended analysis population, or methods for dealing with multiple outcome dimensions or missing data. A study-specific sample-size justification is not reported.
The safety record lists event counts and at-risk counts but does not report death counts, event definitions, or further collection details. These limitations prevent stronger safety interpretation. Taken together, the omissions and missing primary outcome restrict interpretation to the study's intended design and its recorded termination, rather than a comparative treatment result.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Dietary Control Alone Versus Dietary Control Plus Use of Proton Pump Inhibitors to Treat Pediatric Hoarseness — NCT00637416.
- Registry record last updated 2017-01-23; status last verified 2016-11.
- Results first posted 2017-01-23.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The University of Kansas Medical Center sponsored NCT00637416, a phase 4 randomized, double-masked, parallel-group study of dietary control alone versus dietary control plus lansoprazole for pediatric hoarseness. The registry lists dysphonia as the condition and enrollment of 9. The recorded start was 2008-03, primary completion was 2009-07, and the status is terminated.
The primary outcome was change in condition over 3 months, measured using the GRBAS voice assessment protocol. The outcome record says the study was stopped early, data were not collected, and zero participants were analyzed. No primary-outcome comparison or statistical analysis result is reported.
Safety entries list zero serious adverse event cases and zero other adverse event cases in each group; death counts are not reported in the registry record. The reason for termination and further methodological details are not reported.